Cartwright vs. Foster

[StevieInferior]

Rock Cartwright vs. DeShaun Foster

by Aaron Schatz

One of my more controversial statements during this website's first season was my assertion that DeShaun Foster was one of the league's least effective running backs during 2003. The public perception was that Carolina's running game provided a one-two punch, but DVOA ranked Stephen Davis as a league-average back while Foster was down near the bottom of the league.

Foster's low DVOA recently came up in this discussion thread on the excellent fantasy football site footballguys.com, an attempt to list the most underrated and overrated running backs for fantasy football in 2004. DeShaun Foster, who is #36 in the site's expert rankings, is listed as the number one most underrated back:

LHUCKS: "Definitely not a RB2, but #36 would put him at the end of the RB3's... I don't think so. Mr. Foster is one of the most talented RBs in the league, and the ranking of #36 will be scoffed at within the first half of the NFL season... mark my words."

Now, there is the question of course of why this writer feels Stephen Davis is going to be replaced as the starter in Carolina -- even if he declines a bit with age, a RB-by-committee situation (bane of the fantasy player's existence) is more likely. But aside from that, two footballguys.com readers who are also Football Outsiders readers came forward to remind everyone of Foster's low DVOA:

abrecher: "DeShaun Foster is chronically overrated on this board. Check out the stats at Football Outsiders. They rate him the third-worst RB in the league last year (of those with 75+ carries)."

Tick: "I agree that those formulas aren't very applicable for FF for the most part, but I do think they tell a bit about how good an NFL player is... and they say that Foster wasn't a great NFL player last season, while Stephen Davis was good. So in this context (looking at whether Foster will supplant Davis this season), I think it applies."

The mention of our stats got this response:

Colin Dowling: "Are you sure you want to use a complex rankings system that has Rock Cartwright ranked 18th?"

Now, the rushing numbers for 2002 and 2003 are now updated using the new version of DVOA that I introduced last week, and Cartwright has dropped down to 26th, from 15.0% DVOA to 6.5% DVOA. But that's still unexpectedly high for the third-string back on a team not known for its running game.

Dowling's choice of Cartwright of an example of how strange the Football Outsiders rankings are has an unexpected bonus, however. I don't think Mr. Dowling realized this when he mentioned Cartwright, but it turns out Cartwright and Foster might be the two players in the NFL with the most superficially similar numbers -- yet dramatically different DVOA rankings:

So, it turns out that Rock Cartwright and DeShaun Foster give us a great opportunity to delve into the DVOA system and why it is a better measure of a player's true worth to his team (as opposed to your fantasy football team, which -- as footballguys.com commenter Jason Wood points out -- runs on completely different principles).

Now, there are caveats to this analysis. This is the regular season only, and Foster played better (and more memorably) in the playoffs. Yes, Foster was recovering from an injury, and his 2003 performance might not be reflective of his true ability. With those facts noted, though, let's compare Foster to Cartwright down-by-down to see why Cartwright was a much bigger contributor to Washington's offense than Foster was to Carolina's.

That last column may be unclear; it represents the average yards to go for another first down on each back's carries. In actual performance, there isn't much difference between these two on first down. But first down is where Cartwright's much harder schedule has its biggest impact. 29 of Cartwright's carries -- including 15 on first down -- came against our #2 ranked rush defense, Dallas. He had 42 total carries against top ten rush defenses. Foster had only 22 carries against rush defenses in our top ten -- 21 against #6 Detroit and one against #5 Jacksonville.

Cartwright had 11 first downs and three touchdowns on second downs; Foster had only nine first downs, and no touchdowns. Cartwright had only two carries on second down that lost yardage; Foster had eight carries that lost yardage. On 11 second-and-short carries (1-3 yards to go), Cartwright had seven for first downs or touchdowns; on 10 second-and-short carries, Foster had only three first downs.

Some of these differences are due to usage patterns -- Foster had only two red zone carries on second down all year -- but remember, DVOA compares each play to the league average performance in that situation. Cartwright's second-and-goal touchdowns are compared to other second-and-goal situations, and are superior to league-average. Foster's many carries on second-and-long are compared to other carries on second-and-long, and are found wanting. To see exactly how it works, look about four paragraphs down for the "swell math appendix."

Cartwright was better than Foster on third down, but not colossally better, at least when compared to league-average in the situations he faced. Cartwright had 13 first downs (and one touchdown) on third down, Foster had only eight, but that's understandable given that Cartwright carried the ball more often on very short yardage. I will note that Cartwright's DVOA takes a huge hit in the new version of the formula from his one lost fumble, which took place on 3rd-and-goal on the opposing two-yard line (ironically, Carolina was the opponent).

Oops, we almost forgot something:

Foster didn't have a single carry on fourth down, but Cartwright was perfect in his five fourth down carries. I've left one of them off the above table, because it was a 22-yard gain on 4th-and-10 from the New Orleans 49-yard line, the last play of the half. New Orleans could care less if Cartwright ran for 48 yards as long as he didn't run for 49. (The play does count in Cartwright's total season DVOA -- I don't think it makes sense to go through and subjectively determine whether every single play should count or not.) Even if we don't consider this 4th-and-10 play, it is still impressive that Cartwright took the ball four times on 4th-and-1 and had four first downs.

Now we've considered every run by Rock Cartwright and DeShaun Foster in 2003, and shown how Cartwright was more successful than Foster on every down. I could run the numbers for different areas of the field and get the same results. So how did Foster end up with more yards than Cartwright? Simply put, he ran more often in situations where more yards did not mean more success. Here is a breakdown of Cartwright and Foster based on yards to go on each play. Notice how Cartwright had more success in each situation, but was used much more often in short-yardage situations, while Foster ran more often with seven or more yards to go:

Look, it is certainly possible that DeShaun Foster is better than Rock Cartwright. This is just one year of performance for each player, and a part-time year at that. But in 2003, Rock Cartwright was better than DeShaun Foster in pretty much every imaginable situation during the regular season.

That doesn't mean I want Cartwright on my fantasy team -- he's now backing up one of the league's top three backs, and, besides, all those short-yardage runs mean nothing in fantasy football unless they come on the goal line. In fact, according to this Washington Post article, there's a possibility that Cartwright won't even make the Redskins, since he's seen as the kind of "fullback-style" runner that isn't used in a Joe Gibbs offense. Gibbs is the genius, but I think keeping Ladell Betts over Cartwright would be a big mistake.

As for Foster, well, he could have a big season if last year was just an injury recovery year. And I suppose that it is possible that Davis breaks down and the Carolina running attack goes from being two-thirds Davis to being two-thirds Foster. But if last year represents Foster's true ability, Carolina is going to find that depending on Foster doesn't win them a lot of games. DVOA doesn't determine fantasy value, but it does show me that I'd rather have Stephen Davis on my team, and if John Fox agrees, you would rather have Stephen Davis on your fantasy team too.

Swell Math Appendix

To give an example of how the DVOA system works, here are all the runs for Cartwright and Foster on second down with 1-3 yards to go. The three numbers at the end of each line represent the value in "success points" used by the DVOA system to judge each play, the expected value of the league average in that situation (adjusted for opponent), and the difference. First downs are in italics, touchdowns in italics and bold.

With the new version of DVOA introduced last week, Cartwright gets extra credit for his touchdowns, but so do all the other running backs who take the ball on the one-yard line. That extra "success value" is represented in the number given for "expected value."

COMMENTS:

And don't forget "Rock" is great running back name--you could use it as part of the "Madden VOA."

While the end result of DVOA will include players like Rock who aren't on a fan's day-to-day radar, I think these kind of numbers are essential to understanding the overall success or failure of team components.

Is it possible to present the performance of players within formations based on your data? Was Rock always carrying in tight, heavy formations that plan to dive straight ahead or trap? Or does NFL.com largely ignore formation and pre-snap motion in play breakdowns?

Spike | 05/18/2004 - 1:03 PM

Nope, not at this point. There's no formation data in the play by play.

Aaron | 05/18/2004 - 1:06 PM

Hey, that's me!

Tick | 05/18/2004 - 1:41 PM

Thanks for the elaboration, Aaron.

Andrew Brecher | 05/18/2004 - 1:52 PM

very interesting, excellent demonstration of DVOA, I really like there type of articles, even without really trying to understand the math

Josh | 05/19/2004 - 12:33 AM

The obvious question when comparing running backs is, Which one had the better offensive line? I think I'd give a slight edge to the Redskins' o-line, although I love the Panthers' Jordan Gross, who was great as a rookie last year. If anyone disagrees, I'm all ears.

I think it would be a huge mistake for the Skins to get rid of Cartwright. Portis is obviously the main man, and I would think Cartwright would be the starting fullback, with Betts, Trung Canidate and Chad Morton all fighting it out for playing time behind Portis.

MDS | 05/19/2004 - 10:14 AM

Very nice article Aaron.

I think part of the problem for Rock is that he is an uncomfortable runner to watch, whereas Foster is much smoother. Im not saying Foster is faster or better, but whenever I saw Rock with the rock (he he, get it? Im an idiot), it was a much more jerky and ugly style of running. His body language is like the Derek Lowe phenomena. The body language says this guy has nothing, despite the fact that he may be performing quite well. It influences perception.

Pat on the Back | 05/19/2004 - 11:04 AM

http://www.footballoutsiders.com/rockfoster051804.php?view=message&mid=215&showcomment=1&vmid=215

[kam]

Cliffnotes please!

[Ghost of]

Interesting, but I have a hard time ignoring Foster's Herculean effort against Philadelphia or his performance in the Super Bowl.

[DaRock]

Originally posted by kam

Cliffnotes please!

Seriously!...but if this is an argument of the better runningback, it would def. go to Foster..I hope rock stays with the team as our fb if we even will use one, and split time with sellers...I hope rock is a lifelong skin....

[Oldskool]

The only thing that’s ever bothered me about Foster has been the microfracture knee surgery he had in his rookie year. It looks like he has healed back to 100% but its an unproven procedure and no one knows what its long term effects are.

[yank]

Bottom line is when you're choosin up sides, who would you pick first.

Love Rock but Foster has more upside which showed in the Eagles and Patriots playoff games.

[The X-Factor]

Foster definately is the better talent. Rock is a very good 3rd down and goaline back, but I'm not sure how well he could hold up full time. Although Foster has not shown he can stay healthy either, he can develop into one of the leagues top RBs in a few years.

[f_dallas]

Wow.

Fantasy football nerds who have never watched a game or even played peewee ball talk about who is the better backup running back?

I'm Rock will be running this to his agent as their trump card when it's contract time. :laugh:

[@DCGoldPants]

Cartwright and Foster are two different birds.

The Rock is a tweener. He can be in there as a FB....or a RB sometimes. He isn't great at both.

I think Foster will finish the year as the starter in Carolina. Maybe because of performance...but most likely because of injury.

[jrfriedm]

I agree that Rock is a short yardage/goal line back. He's short and stout so he is hard to bring down at the point of attack. Foster on the other hand is more of the speed back that you could see getting a lot of time in long yardage sets.

[Trevor]

There's no comparison in my mind, Foster has a very good upside while Cartwright is an effort player with marginal talent.

[Drex]

I'd take Foster in a heartbeat.

[Troy Fakeman]

Foster is so beast.....

Drex,

CP > DF

[Blondie]

Y'all KNOW when I see Rock's name mentioned in the title of a thread, that I am going to jump into the thread.

This was not what I was expecting.

I won't even call Rock and tell him about this one.

:laugh:

Blondie

[Skeletor The Invincible]

Foster has the potential to be a great running back.

Rock has the potential to be a good third down, goal line back.

Thats it.

You can look at stats all you want, but Foster has far more talent.

Keep in mind this is a fantasy football site, so you never know what the hell they are really talking about. Fantasy football. ugh.

(Rock was still the best running back on the team last year when Betts wasn't playing.)

[Skins26]

Well I cant say I read it all because it was very long.

BUT Deshaun Foster is an absolute freak. There is no way you can say he is overated. He is definitly underated.

This is a bold opinion and i'm sure that I am the only one with it and that nobody else will stand with me on it, but I think that Deshaun Foster has the best RB skills in the league right now. He runs with incredible power and explosiveness and has great speed, i've followed him all through college, I think he's great, and going to be great if he can stay healthy, he looks to have healed well from the knee surgery.

BTW- anyone remember his first ever NFL carry?? It was against us in preseason, it went for a 60-some yard long TD and he stiff armed DG 3 inches into the ground.

[SoCalSkins]

Foster was a preseason favorite to win the Heisman his last year at UCLA. He has Marshall Faulk type ability. I like Rock, but he is not in Foster's class in terms of natural ability.

[Larry]

OTOH, I have to point out:

If I can sumerise the guy's point (and, assuming he has one), it's that, on fourth-and-one, Rock gets 2. On second-and-ten, Foster gets 8.

Foster got more yards, but Rock moved the chains. (Or scored).

(Maybe his fantasy league needs a first-down-per-carry stat.)

(And, I have to admit: I keep having this fantasy of going to a Skins game wearing a customised jersey with #40 and the name "4th and short".)

[PCS]

Sigh. It's a long offseason for everybody I guess.

[NavyDave]

I'll take Da Rock

Foster played in a system that is running back friendly and philly was still injured on the d line front. Heck you talk about potential he has the potential to reinjure that knee.

Da Rock played beind a pass happy line missing starters with no slobberknocker mentality and weak running plays.

Writing Da Rock off this early is foolish considering who he had as a coach if he is wowing them in camp as reported and doing it as a tweener I'm very happy to have him and comparing our 4th running back to a starter is still comical.

[RDSKNfaithfull]

Rock couldnt hold Fosters jock. (no disrespect to rock but like many say he is a tweener)

[spm]

These two are definitely two different birds. Foster is an explosive back who could be a pro bowl tailback. He reminds me of Fred Taylor in that he has all the measurable attributes, incredible athletic skills, but injury problems. Physically, he is a prototype nfl tailback.

Rock will never be an all pro tailback. he is a jack of all trades that improves depth at a lot of positions. He can do a lot of things, and do them at a high level. He is a unique talent; I can't really pinpoint one guy who reminds me totally of Rock. Ironhead Heyward reminded me a little of Rock, but Rock is smaller, quicker, and has more potential as a reciever. Rock's conditioning and attitude are also much better than Heyward's were.

In the end, Foster is a prototype NFL tailback, while Rock is more of a utility player. A healthy Foster could be good in just about any NFL offense. Rock would need an offense tailored to his specific skills to be really successful.

[The Sisko]

Foster is the second coming of Skip Hicks....with injury problems.

I'd take Rock any day. He may not have the measurables Foster does but he's a lot tougher between the tackles and his body won't break apart in a stiff wind either.

[f_dallas]

I'd take Rock any day. He may not have the measurables Foster does but he's a lot tougher between the tackles and his body won't break apart in a stiff wind either.

Excuse me, but what are you basing this on? His name?

Foster is 230 lbs.- just because he's fast doesn't mean he isn't also a pretty good size back.

He was coming off an injury that ends most players careers (based on their declined production) and was still able to get together about 650 yards from scrimmage despite playing behind an all-pro RB.

Foster was better last year, has a higher upside, is younger, faster, just as strong......the list goes on and on.

This is just stupid- Injuries could be the end of Foster, for all I know, but Rock will never amount to anything more than a backup or 3rd stringer on some team- if he even sticks in the NFL.

Foster has the ability to be an Ahmann Green type running back.

[Old Glory]

Originally posted by yank

Bottom line is when you're choosin up sides, who would you pick first.

Love Rock but Foster has more upside which showed in the Eagles and Patriots playoff games.

We've seen way more of Foster then the Rock. With that said, I'd have to choose Foster. But from what I saw of the Rock last season, he should be better behind a Joe Bugal taught offensive line.